Set them from Javascript (into the Applet) instead of trying to
read them in your applet...

In Your applet, create the neccessary  public setter methods for
the parameters your applet need, and in JavaScript on the page,
call the applets setter methods.

To access your applet from js, you must give your applet
(or object) tag an id, and set the tag's "mayScript" attribute.
Then you can call it from JS like this (aircode):

   var myApplet = document.getElementById("myAppletId");
   myApplet.setValue1 = aOneValue;
   myApplet.setValue2 = aSecondValue;